TWI806173B - Polishing pad and method of fabricating semiconductor device using the same - Google Patents

Abstract

A polishing pad is provided, which includes: a polishing layer; 1 g of the polishing layer is added to a 0.3M potassium hydroxide (KOH) aqueous solution, and the nuclear magnetic resonance (NMR) of the processing composition is reacted at 150 ° C for 48 h in a sealed container ) The ¹³ C spectrum includes: a first peak appearing in 15ppm to 18ppm, a second peak appearing in 9ppm to 11ppm, and a third peak appearing in 138ppm to 143ppm; and the third peak is the same as the first The area ratio of the two peaks is from about 5:1 to about 10:1. The polishing pad exhibits physical characteristics conforming to the peak characteristics, so that a polishing rate and defect prevention performance within a target range can be achieved on a polishing process of a polishing object.

Description

Polishing pad and method of manufacturing semiconductor device using same

The present invention relates to a polishing pad used in a polishing process, and the technique of applying the polishing pad to a manufacturing method of a semiconductor device.

A chemical mechanical planarization (Chemical Mechanical Planarization; CMP) or a chemical mechanical polishing (Chemical Mechanical Polishing; CMP) process can be used for various purposes in various technical fields. The CMP process is carried out on the specified polished surface of the polished object, and can be used to planarize the polished surface, remove agglomerated substances, solve crystal lattice damage, remove scratches and pollution sources, etc.

The CMP process technology of the semiconductor process can be classified according to the film quality of the polished object or the shape of the polished surface. For example, it can be divided into single crystal silicon (single silicon) or polysilicon (poly silicon) according to the film quality of the polishing object, and can also be divided into various oxide films or tungsten (W), copper (Cu), aluminum (Al), Ruthenium (Ru), tantalum (Ta) and other metal film CMP process. Furthermore, according to the shape of the polished surface, it can be divided into a process for improving the roughness of the substrate surface, a process for flattening the level difference caused by multilayer circuit wiring, and a device separation process for selectively forming circuit wiring after polishing.

The CMP process can be applied multiple times during the fabrication of semiconductor devices. A semiconductor device includes multiple layers, and each layer includes complex and minute circuit patterns. In addition, in recent semiconductor devices, the size of a single chip has been reduced, and the circuit pattern of each layer has evolved toward complexity and fineness. Therefore, in the manufacturing process of semiconductor devices, the purpose of the CMP process has been expanded to include not only the planarization of circuit wiring, but also the separation of circuit wiring and the improvement of wiring surface, etc. As a result, more precise and reliable CMP performance is being demanded.

This kind of polishing pad used in CMP process is used as a process component that processes the polished surface to the target level by friction. In terms of thickness uniformity of the polished object after polishing, flatness of the polished surface, and polishing quality can be considered as one of the most important factors.

[Problem to be solved by the invention]

One embodiment of the present invention is to provide a polishing pad that can maintain the same level of surface state as the initial polishing surface even after a period of time during the polishing process, so that the polishing performance will not decline for a long time, and based on With appropriate physical properties such as hardness, tensile strength, and elongation, the polishing pad can be used in a polishing process to achieve a desired level of polishing rate and defect prevention.

Another embodiment of the present invention is to provide a method for manufacturing a semiconductor device, the method exhibits high process efficiency in the polishing process of the semiconductor substrate, and in the final polishing result, the polished surface of the semiconductor substrate presents an appropriate Highest polish rate with lowest level of defects. [means used to solve a problem]

In one embodiment of the present invention, a polishing pad is provided, including a polishing layer; 1 g of the polishing layer is added to a 0.3M potassium hydroxide (KOH) aqueous solution, and reacted at a temperature of 150° C. for 48 hours in a sealed container The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition includes: a first peak, occurring in the range of 15 ppm to 18 ppm, a second peak, occurring in the range of 9 ppm to 11 ppm, and a third peak, occurring in the range of 138 ppm to 143 ppm; and the An area ratio of the third peak to the second peak is about 5:1 to about 10:1.

In an embodiment of the present invention, a polishing pad is provided, wherein the area ratio of the first peak to the second peak is about 10:1 to 10:5, and the first peak to the third The area ratio of the peaks is about 10:5 to 10:10.

In one embodiment of the present invention, a polishing pad is provided, wherein the polishing layer comprises a cured product of a preparatory composition containing a urethane-based prepolymer, and the nuclear magnetic resonance (NMR) of the preparatory composition is ¹³ The C spectrum shows the fourth peak and the fifth peak in descending order of peak position (ppm) values from 16ppm to 20ppm, and the area ratio of the fourth peak to the fifth peak is 1:1 to 10:1.

In one embodiment of the present invention, a polishing pad is provided, wherein the preliminary composition comprises reactants of an isocyanate compound and a polyol compound, the isocyanate compound comprises an aromatic diisocyanate compound, and the polyol compound comprises Low-molecular-weight polyols with a weight-average molecular weight (Mw) of about 100 g/mol to less than about 300 g/mol, and high-molecular-weight polyols with a weight-average molecular weight (Mw) of about 300 g/mol to about 1800 g/mol.

In one embodiment of the present invention, a polishing pad is provided, wherein the aromatic isocyanate compound comprises 2,4-toluene diisocyanate (2,4-TDI), and the preparatory composition comprises urethane A prepolymer comprising a first unit structure of toluene-2,4-diisocyanate (2,4-TDI) derived from urethane at one end and urethane derived from both ends At least one of the second unit structures of reacted toluene-2,4-diisocyanate (2,4-TDI).

In an embodiment of the present invention, a polishing pad is provided, wherein the content of isocyanate groups in the preparation composition is 5% by weight to 11% by weight.

其中， 使用凝膠滲透色譜法（GPC）測定所述加工組合物的分子量， 所述Mw是所述解聚組合物的重均分子量， 所述Mn是所述解聚組合物的數均分子量， 所述Mp是所述解聚組合物的峰值（peak）分子量。 In an embodiment of the present invention, there is provided a polishing pad, wherein the polishing layer has a value according to the following formula 1 of 0.1 to 0.6: [Formula 1]

Wherein, the molecular weight of the processing composition is determined using gel permeation chromatography (GPC), the Mw is the weight average molecular weight of the depolymerization composition, and the Mn is the number average molecular weight of the depolymerization composition, The Mp is the peak molecular weight of the depolymerized composition.

In one embodiment of the present invention, a polishing pad is provided, wherein the number average molecular weight (Mn) of the processing composition is 1800g/mol to 2800g/mol, and the weight average molecular weight (Mw) is 2000g/mol to 3000g/mol mol, the peak molecular weight is 2000g/mol to 3000g/mol.

In an embodiment of the present invention, a polishing pad is provided, wherein the processing composition has a degree of dispersion (PDI, Mw/Mn) of 1 to 1.2.

In an embodiment of the present invention, a polishing pad is provided, wherein the polishing layer has a tensile strength of 18 to 22 N/mm ² and a hardness (Shore D) of 35 to 55.

In another embodiment of the present invention, a method for preparing a polishing pad is provided, which includes: a first step of preparing a preparatory composition comprising reactants of an isocyanate compound and a polyol compound, and a second step of preparing a preparation comprising The step of preparing the polishing layer preparation composition of the preparation composition, foaming agent and curing agent, and the third step, the step of preparing a polishing layer by curing the polishing layer preparation composition; 1 g of the The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition added to a 0.3M potassium hydroxide (KOH) aqueous solution and reacted in a sealed container at a temperature of 150°C for 48 hours includes: the first peak, in the range of 15ppm to 18ppm appeared; the second peak, which appeared in 9ppm to 11ppm; and the third peak, which appeared in 138ppm to 143ppm.

In an embodiment of the present invention, a method for preparing a polishing pad is provided, wherein the area ratio of the first peak to the second peak is 10:1 to 10:5, and the area ratio of the first peak to the second peak is The area ratio of the third peak is 10:5 to 10:10.

In one embodiment of the present invention, a method for preparing a polishing pad is provided, wherein the nuclear magnetic resonance (NMR) ¹³ C spectrum of the preparation composition is in the range of 16ppm to 20ppm according to the value of the peak position (ppm) from large to small The fourth peak and the fifth peak are shown sequentially, and the area ratio of the fourth peak to the fifth peak is 1:1 to 10:1.

其中， 使用凝膠滲透色譜法（GPC）測定所述加工組合物的分子量， 所述Mw是所述解聚組合物的重均分子量， 所述Mn是所述解聚組合物的數均分子量， 所述Mp是所述解聚組合物的峰值分子量。 In an embodiment of the present invention, a method for preparing a polishing pad is provided, wherein the value of the polishing layer according to the following formula 1 is 0.1 to 0.6: [Formula 1]

Wherein, the molecular weight of the processing composition is determined using gel permeation chromatography (GPC), the Mw is the weight average molecular weight of the depolymerization composition, and the Mn is the number average molecular weight of the depolymerization composition, The Mp is the peak molecular weight of the depolymerized composition.

In one embodiment of the present invention, a method for preparing a polishing pad is provided, wherein the prepolymer composition is a urethane-based prepolymer, and the isocyanate in the urethane and prepolymer The content of (NCO) groups is 5 to 11% by weight, the composition for preparing the polishing layer in said step ii) contains NH groups, wherein the isocyanate (NCO) groups of the _urethane -based prepolymer are combined with The molar ratio of _NH2 groups of the curing agent is 0.6 to 0.99.

In another embodiment of the present invention, a method for manufacturing a semiconductor device is provided, which includes: providing a polishing pad comprising a polishing layer, and setting the polished surface of the polishing object on the polishing surface of the polishing layer so that the The surface to be polished contacts the polishing surface, and then the step of polishing the polishing object by making it relatively rotate; the polishing object includes a semiconductor substrate, and in the polishing layer, 1 g of the polishing layer is added to 0.3 The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition in an aqueous solution of M potassium hydroxide (KOH) and reacted at 150°C for 48 hours in a sealed container includes: the first peak appears at 15ppm to 18ppm; the second A peak appears at 9ppm to 11ppm; and a third peak appears at 138ppm to 143ppm, and an area ratio of the third peak to the second peak is 5:1 to 10:1.

其中， 使用凝膠滲透色譜法（GPC）測定所述加工組合物的分子量， 所述Mw是所述解聚組合物的重均分子量， 所述Mn是所述解聚組合物的數均分子量， 所述Mp是所述解聚組合物的峰值分子量。 In an embodiment of the present invention, a method of manufacturing a semiconductor device is provided, wherein the polishing layer has a value of 0.1 to 0.6 according to the following formula 1: [Formula 1]

Wherein, the molecular weight of the processing composition is determined using gel permeation chromatography (GPC), the Mw is the weight average molecular weight of the depolymerization composition, and the Mn is the number average molecular weight of the depolymerization composition, The Mp is the peak molecular weight of the depolymerized composition.

In an embodiment of the present invention, a method for manufacturing a semiconductor device is provided, wherein the semiconductor substrate includes a silicon dioxide (SiO ₂ ) film, and the polished surface is a surface of the silicon dioxide (SiO ₂ ) film On the surface, the average polishing rate of the silicon dioxide film is 1500 Å/min to 2500 Å/min, and after the polishing of the polished surface, there are less than 5 surface defects.

In an embodiment of the present invention, a method for manufacturing a semiconductor device is provided, wherein the rotational speeds of the polishing object and the polishing pad are respectively 10 rpm to 500 rpm.

In one embodiment of the present invention, a method for manufacturing a semiconductor device is provided, which further includes the step of supplying polishing slurry on the polishing surface of the polishing layer, and the supply flow rate of the polishing slurry is 10ml/min to 1000mL/min. [Invention effect

The polishing pad includes a polishing layer of a chemically bonded structure and a cross-linked structure, corresponding to peak characteristics exhibited by a processing composition treated with the polishing pad under prescribed conditions, so that the polishing surface of the polishing layer can exhibit appropriate hardness , so that the polishing rate and polishing flatness within the target range can be presented during the polishing process of the polishing object. In addition, during the polishing process, as time goes by, the polished surface still maintains the original surface state, so it has the advantage that the polishing performance will not decline for a long time.

The method of manufacturing a semiconductor device using the polishing pad exhibits high process efficiency in the polishing process of a semiconductor substrate as a polishing object, and in the final polishing result, the polished surface of the semiconductor substrate exhibits high polishing flatness Degree and minimum level of defects.

According to the following embodiments, the advantages, features and implementation methods of the present invention will be more clearly understood. However, the present invention is not limited to the following exemplary embodiments, but can be implemented in various forms, and these exemplary embodiments are provided only to make the present invention more complete, and to fully inform those skilled in the art to which the present invention pertains. The scope of the present invention is only provided, and the present invention will be defined by the appended claims.

In order to clearly express each layer and region in the drawing, the thickness is exaggerated and shown. And in the accompanying drawings, for convenience of description, the thicknesses of some layers and regions are shown exaggeratedly. Throughout the specification, the same reference numerals denote the same constituent elements.

In addition, in this specification, when a part of a layer, film, region, plate, etc. is referred to as being “on” or “over” another part, this includes not only the case of “just above” but also the case of intervening other parts of the situation. Conversely, when a part is said to be "directly above" another part, it means that there is no other part in between. Also, when a part of a layer, film, region, plate, etc. is referred to as being "under" or "beneath" another part, this includes not only the case of "just below" but also the case of other parts in between. Conversely, when a part is said to be "directly below" another part, it means that there is no other part in between.

In addition, in this specification, in the area ratio of the peak of the nuclear magnetic resonance (NMR) spectrum, if the average value of the area ratio calculated at least 5 times for the same polishing layer by the same method is within the corresponding range, it should be regarded as The area ratio of the peaks of the nuclear magnetic resonance (NMR) spectrum is within the scope of the patent application. In addition, the area ratio of the peaks can be obtained from the integration value of corresponding peaks in a nuclear magnetic resonance (NMR) spectrum.

In one embodiment of the present invention, a polishing pad is provided, which includes: a polishing layer; 1 g of the polishing layer is added to an aqueous solution of potassium hydroxide (KOH) with a concentration of 0.3 molar, and placed in a sealed container The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition reacted at a temperature of 150°C for 48 hours includes: the first peak appears at 15ppm to 18ppm, the second peak appears at 9ppm to 11ppm, and the third peak appears at 138ppm to 143ppm; and the area ratio of the third peak to the second peak is about 5:1 to about 10:1.

The polishing layer is a cured product composed of a compound with a prescribed chemical structure, so the final polishing performance such as the polishing rate and the degree of defects may depend on the chemical structure of the compound and the repeating unit constituting the chemical structure. Each bonding structure and binding force. The compound contained in the polishing layer has chemical bonding structures of various shapes, but when the polishing layer is processed under predetermined processing conditions, the chemical bonds are separated or remain unchanged according to the binding force of each bonding structure. The shape of the Nuclear Magnetic Resonance (NMR) ¹³ C spectrum of the processing composition of the polishing layer will thus vary.

Specifically, the polishing layer according to an embodiment is characterized in that 1 g of the polishing layer is added to an aqueous solution of potassium hydroxide (KOH) with a concentration of 0.3 molar, and reacted in a sealed container at a temperature of 150°C The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition after 48 hours includes: the first peak, which appears in 15ppm to 18ppm, the second peak, which appears in 9ppm to 11ppm, and the third peak, which appears in 138ppm to 143ppm; And an area ratio of the third peak to the second peak is about 5:1 to about 10:1. That is, the polishing layer is composed of a compound having a chemical bonding structure corresponding to the spectral characteristics, so that the polishing performance of the polishing pad can be greatly improved. More specifically, the polishing layer has a polymer binding degree when the area ratio of the second peak to the third peak in the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition satisfies the condition, Accordingly, physical properties such as hardness and elongation are exhibited accordingly, and as a result, polishing performance such as polishing rate (RR) at the target level can be realized.

For example, the area ratio of the third peak to the second peak may be about 5:1 to about 10:1, for example, may be about 5:1 to 8:1. From the result that the area ratio of the third peak to the second peak satisfies the above range, it can be known that the polishing layer is partially decomposed under predetermined conditions and has a repeating unit exhibiting the chemical binding force of the peak, Compounds having a chemical structure corresponding to the area ratio as a whole are also included. Accordingly, the polishing layer can have appropriate hardness and elongation, and as a result, the desired polishing rate and defect reduction effect can be achieved.

In one embodiment, in the processing composition, the area ratio of the first peak to the second peak is 10:1 to 10:5, and the area ratio of the first peak to the third peak is The ratio is 10:5 to 10:10.

For example, the area ratio of the first peak to the second peak may be about 10:1 to about 10:5, for example, about 10:1.00 to about 10:1.60, for example, about 10:1.00 More than and about 10: 1.60 or less.

For example, the area ratio of the first peak to the third peak can be 10:5 to 10:10, for example, it can be greater than 10:5.00, and it can be about 10:10.00 or less, for example, it can be about 10:5.60 to about 10:9.00.

When the area ratio of the third peak to the second peak of the processed composition satisfies the range, the area ratio of the first peak to the second peak and the area ratio of the first peak to the When the area ratio of the third peak also satisfies the above-mentioned range, it can be known that the polishing layer is cured with an appropriate degree of curing in the curing step of preparing the polishing layer, so that the polishing layer exhibits appropriate hardness and elongation. rate, as a result, the target polishing rate and defect reduction effect can be achieved.

In addition, in the processing composition, 1 g of the polishing layer was added to an aqueous solution of potassium hydroxide (KOH) with a concentration of 0.3 mol and treated under the condition of reacting at a temperature of 150° C. for 48 hours in a sealed container. The resulting processed composition has a higher correlation between the nuclear magnetic resonance (NMR) ¹³ C spectrum and the polishing performance of the final polishing pad than the processed composition processed under other conditions.

The nuclear magnetic resonance of the processing composition can be determined by comprehensively adjusting the type and content of raw material monomers, step temperature and pressure conditions, the type and content of additives such as curing agent and foaming agent, and other factors during the process of preparing the polishing layer. (NMR) ¹³ C spectrum.

其中， 將所述1g的拋光層加入15ml的0.3M濃度的KOH水溶液中，並在密封容器中以150℃的溫度解聚48小時後，使用所述凝膠滲透色譜法（GPC）來測定瞭解聚後的組合物的分子量， 所述Mw是所述解聚組合物的重均分子量， 所述Mn是所述解聚組合物的數均分子量， 所述Mp是所述解聚組合物的峰值（peak）分子量。 In the polishing pad of an embodiment of the present invention, the value of the polishing layer according to Equation 1 may be 0.1 to 0.6: [Equation 1]

Wherein, 1 g of the polishing layer was added to 15 ml of 0.3 M KOH aqueous solution, and depolymerized at a temperature of 150° C. for 48 hours in a sealed container, and the gel permeation chromatography (GPC) was used to determine the solution The molecular weight of the composition after polymerization, the Mw is the weight average molecular weight of the depolymerization composition, the Mn is the number average molecular weight of the depolymerization composition, and the Mp is the peak value of the depolymerization composition (peak) molecular weight.

According to the type and content of the curing agent that can be included in the preparation of the polishing layer, the curing reactive groups such as amino (-NH ₂ ) and alcoholic hydroxyl (-OH) of the curing agent and the isocyanate group of the prepolymer ( -NCO) and determines the structure of the compound in the polishing layer.

The final urethane cured structure of the polishing pad is determined by the factors described above. With the final urethane cured structure, the polishing layer can exhibit physical/mechanical properties such as hardness, tensile strength, and elongation.

The polishing pad is a process product that can be used in various polishing processes, and the defect rate and production quality of the process products manufactured by using the polishing pad are largely affected by the physical properties of the polishing pad. In various polishing processes, it is necessary to fine-tune the physical properties of the surface of the polishing layer, so that it can be used not only for bulk (bulk) level polishing processes, but also for micro (micro) and nano (nano) level ultra-precision In the polishing process, even if there is no significant difference in the absolute values of the physical properties, there may be very large differences in the final polishing physical properties.

The polishing layer is a cured product composed of a compound having a predetermined chemical structure, and differs depending on the chemical structure of the compound and the respective bonding structures and binding forces of repeating units constituting the chemical structure.

The compounds contained in the polishing layer have various types of chemical bonding structures, and when the polishing layer is processed under prescribed processing conditions, the bonding may separate or remain unchanged depending on the binding force of the respective bonding structures. Utilizing this characteristic, after depolymerizing the polishing layer of the present invention, measure the weight average molecular weight (Mw), number average molecular weight (Mn) and peak molecular weight (Mp) of the composition after depolymerization, and compare these values Substituting Formula 1 of the present invention, the polishing layer exhibits physical properties due to the chemical structure of the compound constituting the polishing layer in the case where the calculated value is included in the scope of the present invention.

The physical and mechanical properties of the polishing layer are closely related to the occurrence of defects in the semiconductor substrate during the polishing process. Although the average polishing rate and pad removal rate can be improved based on the physical and mechanical properties of the polishing layer, relatively speaking, it will also lead to an increase in the occurrence of defects on the semiconductor substrate.

Specifically, the polishing pad (pad) used in the CMP process can support the processing pressure applied on the semiconductor substrate, and transfer the slurry (Slurry) to the wafer surface. And relative to the surface of the wafer, the polishing particles contained in the slurry are pressurized vertically and roll in the horizontal direction, so that the polishing process can be carried out smoothly.

The polishing pad that performs this function undergoes elastic deformation and viscoelastic deformation due to the applied load, the elastic deformation and viscoelastic deformation are deformation characteristics of polymer materials, and the polishing pad is in direct contact with the semiconductor substrate during polishing , thus affecting the polishing result.

In the case of the polishing pad of the present invention, hardness, tensile strength, and elongation properties are particularly excellent, so that the occurrence of defects on the semiconductor substrate can be reduced.

According to the formula 1, when the polishing layer is depolymerized under specific depolymerization conditions, the structure of the compound constituting the polishing layer is decomposed under the depolymerization conditions, and it can be confirmed by confirming the value of the decomposed compound The physical and/or chemical properties of the polishing layer.

That is, it is a physical and/or chemical index given to the polishing layer due to its chemical structure, etc., by the compound that makes up the polishing layer. When the value of the formula 1 is too low or too high, the polishing layer does not have Appropriate hardness and elongation, so that in the polishing process using the polishing pad, the polishing layer will have unsuitable physical and/or chemical effects on the polished object, which may lead to a decrease in the final polishing performance.

The value of the formula 1 may be 0.1 to 0.6, preferably, 0.2 to 0.5. When the value of the formula 1 is too low, the hardness of the polishing layer is too high or the elongation is too low, so that the probability of defects such as scratches occurring on the surface of the film to be polished during polishing may increase. In addition, when the value of the above formula 1 is too high, there may be a problem that the polishing rate does not reach a desired level. That is, when the value of the formula 1 satisfies the range, the polishing layer can exhibit appropriate hardness and elongation. Based on this, the polishing layer can exhibit appropriate hardness and elongation for the film to be polished during the polishing process. Elasticity and physical properties, so that it can show favorable effects in terms of polishing rate, pad removal rate, and defect prevention.

The polishing layer of the present invention has a tensile strength of 18 to 22 N/mm ² and a hardness (Shore D) of 35 to 55. Based on the physical/mechanical properties of the polishing layer, defects of the semiconductor substrate can be reduced during the polishing process.

Specifically, the polishing layer is depolymerized under the following conditions. When the depolymerized composition is measured by GPC, the number average molecular weight (Mn) is 1800g/mol to 2800g/mol, preferably 2000g/mol to 2500g/mol mol, more preferably from 2100 g/mol to 2350 g/mol. In addition, the weight average molecular weight (Mw) is 2000 g/mol to 3000 g/mol, preferably 2300 g/mol to 2700 g/mol, more preferably 2400 g/mol to 2600 g/mol. The peak molecular weight is from 2000 g/mol to 3000 g/mol, preferably from 2300 g/mol to 2700 g/mol, more preferably from 2400 g/mol to 2600 g/mol.

When the number-average molecular weight and weight-average molecular weight of the depolymerized composition satisfy the range, the value of the formula 1 is satisfied, and since the range of the formula 1 is satisfied, it can have appropriate hardness and elongation, which As a result, the intended polishing rate and defect reduction effect can be achieved.

Specifically, the composition of the deagglomerated polishing layer is characterized by a degree of dispersion (PDI, Mw/Mn) of 1.2 or less. Generally, when the degree of dispersion of a polymer is measured, the closer the measured value is to 1, the wider the molecular weight distribution of the polymer is. Usually, when the cured polymer is decomposed by depolymerization, the position of the bond break of the cured polymer under the depolymerization condition will be different, so that the polymer exists in a distributed form.

In contrast, the polishing layer of the present invention is a polishing layer comprising a cured product obtained by curing a polyurethane prepolymer, and the dispersion value of the polymer obtained after the bond of the compound is broken by depolymerization of the cured product is Below 1.2, it shows a monodisperse distribution. That is, the polishing layer of the present invention is characterized by being depolymerized and degraded to have a narrow molecular weight distribution.

Specifically, the peak molecular weight of the composition of the depolymerized polishing layer is 2000 g/mol to 3000 g/mol, preferably 2300 g/mol to 2700 g/mol, more preferably 2400 g/mol to 2600 g/mol . The weight average molecular weight (Mw) is 2000 g/mol to 3000 g/mol, preferably 2300 g/mol to 2700 g/mol, more preferably 2400 g/mol to 2600 g/mol.

In order to use the polishing pad for the CMP polishing process, a step of confirming the average polishing rate and pad removal rate by directly performing a polishing performance test on the polishing pad and judging whether to use the polishing pad is required.

This means that when selecting a polishing pad for a polishing process, it is necessary to confirm the polishing performance by conducting a polishing performance test, which is a time-consuming and cost-intensive step.

On the contrary, in the present invention, after depolymerization, the number average molecular weight (Mn), weight average molecular weight (Mw) and peak molecular weight (Mp) are measured by using the GPC measurement results, so that the polishing can be selected. pad, and the polishing pad capable of reducing defects occurring on the surface of the semiconductor substrate during the polishing process can be selected by using the value of the above-mentioned formula 1.

This will allow the performance of the polishing pad to be predicted without directly testing the polishing performance, thus greatly simplifying the steps in the process application of the polishing pad.

1A and 1B are diagrams schematically showing a cross-section of the polishing pad according to an embodiment. Referring to FIG. 1A , the polishing pad 100 includes the polishing layer 10 and may include a buffer layer 20 on a surface of the polishing layer 10 . The polishing layer 10 is in the shape of a sheet with a predetermined thickness, and includes: a first surface (hereinafter also referred to as a "polishing surface") 11, which functions as a polishing surface that is in direct or indirect contact with the polished surface of the polishing object; Surface 12, the back side of the first surface 11.

In an embodiment, the first surface 11 may include grooves 13 processed to a depth smaller than the thickness of the polishing layer 10 . The grooves 13 may have concentric circular structures formed at regular intervals from the center to the end of the polishing layer 10 based on the planar structure of the first surface 11 . In another embodiment, the groove 13 may have a radial structure continuously formed from the center to the end of the polishing layer 10 based on the planar structure of the first surface 11 . In yet another embodiment, the groove 13 may have both the concentric circular structure and the radial structure. The groove 13 can play the following role: during the polishing process using the polishing pad 100, adjust the fluidity of the polishing liquid or slurry supplied to the first surface 11, or adjust the polishing surface and The physical properties of the contact area of the surface being polished adjust the polishing result.

In one embodiment, the polishing layer 10 may have a thickness of about 0.8mm to about 5.0mm, for example, about 1.0mm to about 4.0mm, for example, about 1.0mm to 3.0mm, for example, about 1.5mm to about 3.0mm mm, eg, about 1.7 mm to about 2.7 mm, eg, about 2.0 mm to about 3.5 mm.

The polishing layer 10 may be a porous structure including a plurality of pores. The plurality of pores may have an average particle diameter of about 5 μm to about 50 μm, for example, about 5 μm to about 40 μm, for example, about 10 μm to about 40 μm, for example, about 10 μm to about 35 μm, but not limited thereto. A part of the plurality of pores is exposed from the polishing surface of the polishing layer to the outside, and is expressed in the form of fine recesses (not shown) that are different from the grooves 13, and the fine recesses can be formed on the polishing pad. During use, together with the groove 13, the fluidity and storage space of the polishing liquid or polishing slurry can be determined, so that it can function as an adjustment factor of polishing characteristics.

The polished surface (first surface 11 ) may have a predetermined surface roughness due to the fine recesses that differ from the grooves 13 . In an embodiment, the surface roughness (Ra) of the polishing surface (first surface 11 ) may be about 3 μm to about 1 mm. For example, the surface roughness (Ra) of the polishing surface (first surface 11 ) may be about 3 μm to about 20 μm, for example, may be about 3 μm to about 10 μm.

The buffer layer 20 is disposed on the second surface 12 of the polishing layer 10 to support the polishing layer 10 and relieve the external pressure or impact transmitted to the polished surface during the polishing process. Therefore, during the polishing process using the polishing pad 100 , it is helpful to prevent the polishing object from being damaged and having defects.

In one embodiment, the buffer layer 20 may have a thickness of about 0.5mm to about 2.5mm, for example, about 0.8mm to about 2.5mm, for example, about 1.0mm to about 2.5mm, for example, about 1.0mm to about 2.0mm, eg, about 1.2mm to about 1.8mm.

Referring to FIG. 1B , in one embodiment, the polishing pad 200 may include the polishing layer 10 and the buffer layer 20 , and may also include an interface between the polishing layer 10 and the buffer layer 20 The first adhesive layer 30. For example, the first adhesive layer 30 may be derived from a heat-sealing adhesive, but is not limited thereto.

The polishing pad 200 may further include a second adhesive layer 40 disposed on the second surface 12 of the polishing layer 10 . The second adhesive layer 40 is a structure for adhering the polishing pad to the flat plate of the polishing device, and can be arranged directly above the second surface 12 of the polishing layer 10, or as shown in FIG. 1B , disposed on other layers such as the buffer layer 20 on the polishing layer 10 . For example, the second adhesive layer 40 may be derived from a pressure sensitive adhesive, but not limited thereto.

In one embodiment, the polishing pad may include a penetrating region penetrating the uppermost layer and the lowermost layer thereof. The penetrating region serves as a structure for detecting a polishing end point during use of the polishing pad, and light with a specified wavelength condition can pass through the penetrating region. In an embodiment, a window may be provided in the through region. The transmittance of the light transmission window to any one of wavelengths of light from about 500 nm to about 700 nm may exceed about 30%, for example, may be about 40% to about 80%.

The polishing layer may include a cured product of a preliminary composition containing a urethane-based prepolymer. In one embodiment, the preparatory composition may further include a curing agent and a foaming agent. The “prepolymer” refers to a relatively low molecular weight polymer whose degree of polymerization is interrupted at an intermediate stage in order to facilitate molding when preparing a cured product. The prepolymer itself can be finally shaped into a cured product through additional curing processes such as heating and/or pressure, or it can be mixed with other polymeric compounds, such as different types of monomers or different types of prepolymers and other additional compounds And react to finally shape into a cured product.

In one example, the urethane-based prepolymer may be prepared by reacting an isocyanate compound with a polyol compound.

The isocyanate compound used in preparing the urethane-based prepolymer may be one selected from the group consisting of aromatic diisocyanate, aliphatic diisocyanate, alicyclic diisocyanate, and combinations thereof. In one embodiment, the isocyanate compound may include aromatic diisocyanate.

The isocyanate compound, for example, may contain 2,4-toluene diisocyanate (2,4-toluenediisocyanate, 2,4-TDI), 2,6-toluene diisocyanate (2,6-toluenediisocyanate, 2,6- TDI), naphthalene-1,5-diisocyanate (naphthalene-1,5-diisocyanate), p-phenylenediisocyanate (p-phenylenediisocyanate), dimethylbiphenyl diisocyanate (tolidinediisocyanate), 4,4'-diphenylmethane Diisocyanate (4,4'-diphenylmethanediisocyanate), hexamethylenediisocyanate (hexamethylenediisocyanate), dicyclohexylmethanediisocyanate (dicyclohexylmethanediisocyanate), 4,4'-dicyclohexylmethanediisocyanate (4,4'-dicyclohexylmethanediisocyanate, H ₁₂ MDI), isophorone diisocyanate (isoporonediisocyanate) and a combination thereof.

The "polyol" refers to a compound containing at least two hydroxyl groups (-OH) per molecule. In one embodiment, the polyol compound may include a diol compound containing 2 hydroxyl groups, ie, diol or glycol.

The polyol compound, for example, may include polyols selected from polyether polyols, polyester polyols, polycarbonate polyols, acryl polyols and one of the groups consisting of their combinations.

The polyol compound, for example, may contain polytetramethylene ether glycol (PTMG), polypropylene ether glycol, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,2- Butanediol, 1,3-butanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 3-methyl-1 , 5-pentanediol, 1,6-hexanediol, diethylene glycol (DEG), dipropylene glycol (DPG), tripropylene glycol, polypropylene glycol, and combinations thereof.

The polyol compound may have a weight average molecular weight (Mw) of about 100 g/mol to about 3000 g/mol. For example, the polyol may have a weight average molecular weight (Mw) of about 100 g/mol to about 3000 g/mol, eg, about 100 g/mol to about 2000 g/mol, eg, about 100 g/mol to about 1800 g/mol.

In one embodiment, the polyol compound may include a low molecular weight polyol with a weight average molecular weight (Mw) of about 100 g/mol or more and less than about 300 g/mol and a weight average molecular weight (Mw) of about 300 g/mol or more and It is a high molecular weight polyol below about 1800 g/mol. In an embodiment, the high molecular weight polyol may comprise: a first high molecular weight polyol having a weight average molecular weight (Mw) of about 500 g/mol and not more than about 800 g/mol; and a weight average molecular weight (Mw) greater than about 800 g/mol and up to about 1800 g/mol of the second highest molecular weight polyol. In this case, the polyol compound can form an appropriate cross-linked structure in the urethane-based prepolymer, and the preparatory composition containing the urethane-based prepolymer is A polishing layer cured under certain conditions may be more conducive to achieving the effect. That is, since the polyol compound has an appropriate crosslinked structure, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition obtained by treating the polishing layer under prescribed conditions may exhibit the peak area ratio characteristic, and Excellent polishing characteristics corresponding to the characteristics can be realized.

The urethane-based prepolymer may have a weight average molecular weight (Mw) of about 500 g/mol to about 3000 g/mol. The urethane-based prepolymer, for example, may have a weight average molecular weight (Mw) of about 600 g/mol to about 2000 g/mol, for example, about 800 g/mol to about 1000 g/mol. In the case where the urethane-based prepolymer has a degree of polymerization corresponding to the weight average molecular weight (Mw), the polishing layer formed by curing the preparatory composition under specified process conditions may be more beneficial Has a chemically bonded structure that achieves the excellent polishing characteristics.

In one embodiment, the isocyanate compound used to prepare the urethane-based prepolymer may include an aromatic diisocyanate compound, and the aromatic diisocyanate compound, for example, may include 2,4-toluene diisocyanate ( 2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI). In addition, the polyol compound used to prepare the urethane-based prepolymer, for example, may include polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

In another embodiment, the isocyanate compound used to prepare the urethane-based prepolymer may include an aromatic diisocyanate compound and an alicyclic diisocyanate compound, for example, the aromatic diisocyanate compound may include 2 , 4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), the alicyclic diisocyanate compound may include dicyclohexylmethane diisocyanate (H ₁₂ MDI). In addition, the polyol compound used to prepare the urethane-based prepolymer, for example, may include polytetramethylene ether glycol (PTMG) and diethylene glycol (DEG).

In the preliminary composition, the total amount of the polyol compound may be about 100 parts by weight relative to 100 parts by weight of the total amount of the isocyanate compound in all components used to prepare the urethane-based prepolymer. Parts by weight to about 250 parts by weight, for example, about 120 parts by weight to about 250 parts by weight, for example, about 120 parts by weight to about 240 parts by weight, for example, about 150 parts by weight to about 240 parts by weight, for example, about 190 parts by weight to about 240 parts by weight.

In the preliminary composition, when the isocyanate compound used to prepare the urethane-based prepolymer contains the aromatic isocyanate compound, and the aromatic isocyanate compound contains 2,4-toluene diisocyanate (2,4-TDI) and 2,6-toluene diisocyanate (2,6-TDI), the content of the 2,6-toluene diisocyanate (2,6-TDI) relative to the 2,4- 100 parts by weight of toluene diisocyanate (2,4-TDI), can be about 1 part by weight to about 40 parts by weight, for example, about 1 part by weight to about 30 parts by weight, for example, about 3 parts by weight to about 28 parts by weight, For example, about 1 part by weight to about 10 parts by weight.

In the preliminary composition, when the isocyanate compound used to prepare the urethane-based prepolymer includes the aromatic isocyanate compound and the alicyclic isocyanate compound, the alicyclic isocyanate The content of the compound may be about 5 parts by weight to about 30 parts by weight, for example, about 10 parts by weight to about 25 parts by weight relative to 100 parts by weight of the entire aromatic isocyanate compound.

The isocyanate group content (NCO%) of the preparatory composition may be from about 5% to about 11% by weight, eg, from about 5% to about 10%, eg from about 5% to about 8.5%. The isocyanate group content refers to the weight percentage of the isocyanate group (—NCO) existing as free radicals without polyurethane reaction in the total weight of the preparatory composition. The isocyanate group content (NCO%) of the preparatory composition can be adjusted comprehensively by adjusting the types and contents of the isocyanate compound and polyol compound used to prepare the urethane-based prepolymer. The urethane The temperature, pressure, time and other process conditions of the preparation process of the urethane-based prepolymer, as well as the types and contents of additives used in the preparation of the urethane-based prepolymer are designed.

In one embodiment, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the preparation composition shows the fourth peak and the fifth peak in descending order of peak position (ppm) values in the range of 16ppm to 20ppm, An area ratio of the fourth peak to the fifth peak may be about 1:1 to about 10:1.

Specifically, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the preliminary composition may have a fourth peak within a range of 17.5 ppm to 20.0 ppm, and may have a fifth peak within a range of 16 ppm to 17.5 ppm. For example, the area ratio of the fourth peak to the fifth peak may be about 1:1 to about 10:1, for example, about 3:1 to 10:1, for example, about 3.5:1 to about 9:1 , for example, about 3.5:1 to 8:1. The polishing layer formed by curing the preparatory composition with such peak characteristics under specified process conditions may be more conducive to exhibit suitable physical properties in terms of achieving target levels of polishing rate, polishing flatness, and defect reduction effect.

In one embodiment, when performing the GPC determination of the preparation composition, the weight average molecular weight (Mw) may be 3800 to 4700, the number average molecular weight (Mn) may be 2800 to 3500, and the peak molecular weight (Mp) may be Can be 3500 to 4500.

Specifically, the preparatory composition is used as a urethane-based prepolymer, and the polishing layer formed by curing the preparatory composition meeting the characteristics of the GPC measured value range under specified process conditions may be more conducive to achieving the purpose Appropriate physical properties in terms of level of polishing rate, polishing flatness, and defect reduction effect.

The preliminary composition is a composition comprising the urethane-based prepolymer, and the chemical bonding structure in the cured structure of the polishing layer may be based on the chemical structure itself of the urethane-based prepolymer; And/or the concentration of free functional groups contained in the urethane-based prepolymer and the free functional groups contained in residual unreacted monomers vary. On the other hand, even if the monomers constituting the urethane-based prepolymer and the remaining unreacted monomers are the same in kind or content, the chemical bonding structure in the cured structure of the polishing layer is consistent with nuclear magnetic resonance based on this. (NMR) The peak characteristics of the ¹³ C spectrum vary depending on: the process conditions used to prepare the urethane-based prepolymer; the curing process conditions used to prepare the polishing layer; or the conditions used to prepare the The processing conditions and the like of the above-mentioned processing composition.

FIG. 3 is a schematic view illustrating an embodiment of the preparation composition 50 , the cured structure 60 constituting the polishing layer, and the processing composition 70 , to illustrate the above. Referring to FIG. 3, the preparatory composition 50 is prepared by reacting monomer A, monomer B, monomer C, and monomer D, for example, may include a first prepolymer (A-B-C-B-A), a second prepolymer Polymer (A-B-C-B-D) and unreacted monomer D. In the event that the type of monomer used to prepare the preliminary composition 50 changes, the chemical structure of the prepolymer also changes. In addition, even when the same monomer is used as a raw material according to reaction conditions such as temperature, pressure, and time used to prepare the preliminary composition 50, the structure of the prepolymer and the type of unreacted monomer may vary. Something has changed. Next, after adding additives E and the like to the preliminary composition 50, curing is carried out under prescribed curing process conditions such as temperature, pressure, time, etc., to form a longer chain structure than the prepolymer Cured structure 60 with a cross-linked structure. The chemical structure of the cured structure 60 may also vary depending on the type of the additive and/or the process conditions used to prepare the polishing layer. Next, processing composition 70 is obtained by treating said cured structure 60 under the first conditions. At least a portion of the bonding structure of the cured structure 60 is broken and decomposed due to the first condition, thereby obtaining a structure comprising structure 1 (A-B-C), structure 2 (B-A-E-D-A-B) and structure 3 (C-B-A). Final processing composition 70. In this case, the processed composition treated under conditions other than the first condition contains structures having different chemical structures from the above-mentioned structure 1 , structure 2 , and structure 3 .

That is, the nuclear magnetic resonance (NMR) of the processing composition treated under the condition that 1 g of the polishing layer was added to a 0.3 M potassium hydroxide (KOH) aqueous solution and reacted at a temperature of 150° C. for 48 hours in a sealed container ¹³ The peak characteristic of the C spectrum is the characteristic that the following conditions are organically related and presented comprehensively: the preparation composition used to prepare the polishing layer; the urethane-based prepolymer used to prepare the preparation composition The type and content of the monomer; various process conditions during the preparation of the preparatory composition and the preparation of the polishing layer; the processing conditions for obtaining the processing composition, etc. However, the technical purpose of the polishing pad of one embodiment is to propose a correlation between the peak characteristics exhibited by the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition and the final polishing performance of the polishing pad relationship, that is, when the peak characteristic satisfies the condition, the polishing performance reaches the target level, and within the scope of satisfying the target, even if a slightly different monomer type, content and process conditions are used, the It should not be regarded as departing from the scope of claims of the present invention.

In one embodiment, the isocyanate compound used to prepare the urethane-based prepolymer may include an aromatic diisocyanate compound, and the aromatic diisocyanate compound may include 2,4-toluene diisocyanate (2,4 -TDI) and 2,6-toluene diisocyanate (2,6-TDI). At this time, the urethane-based prepolymer may include a first unit structure of 2,4-TDI derived from a one-terminal urethane reaction, a second unit derived from a one-terminal urethane reaction of 2,6-TDI. structure and at least one of the third unit structure of 2,4-TDI derived from two-terminal urethane reaction. Here, "polyurethane reaction at one end" means that one of the two isocyanate groups of the diisocyanate undergoes polyurethane reaction, and "polyurethane reaction at both ends" means that both isocyanate groups of the diisocyanate undergo polyurethane reaction. reaction. In addition, the "unit structure" refers to at least one or more unit structures contained in the chemical structure of the main chain of the prepolymer.

In one embodiment, the urethane-based prepolymer may comprise a plurality of prepolymers with different repeating structures, and each prepolymer may independently comprise the first unit structure, the second unit structure and At least one of the third unit structures. Thus, the polishing layer comprising a cured product of the preliminary composition may be more conducive to achieving a desired level of polishing performance.

The nuclear magnetic resonance (NMR) ¹³ C spectral peak characteristics of the preliminary composition, as described above, are composed of the type and content of the monomers constituting the urethane-based prepolymer, the urethane-based prepolymer The type and content of the remaining unreacted monomers, the chemical bonding structure of the urethane-based prepolymer, and the reaction process conditions for preparing the urethane-based prepolymer are determined comprehensively.

The curing agent is a compound for chemically reacting with the urethane-based prepolymer to form a final cured structure of the polishing layer, for example, may include an amine compound or an alcohol compound. Specifically, the curing agent may contain one selected from the group consisting of aromatic amines, aliphatic amines, aromatic alcohols, aliphatic alcohols, and combinations thereof.

For example, the curing agent may include 4,4'-methylene bis (2-chloroaniline) (4-4'-methylenebis (2-chloroaniline), MOCA), diethyltoluenediamine (diethyltoluenediamine, DETDA), diaminodiphenylmethane (diaminodiphenylmethane), dimethylthiotoluene diamine (dimethyl thio-toluene diamine, DMTDA), propanediol bis p-aminobenzoate (propanediol bis p-aminobenzoate), methylene Methylene bis-methylanthranilate, diaminodiphenylsulfone, m-xylylenediamine, isophoronediamine, ethylenediamine (ethylenediamine), diethylenetriamine, triethylenetetramine, polypropylenediamine, polypropylenetriamine, bis(4-amino-3-chlorophenyl)methane (bis(4-amino-3-chlorophenyl)methane) and combinations thereof.

The content of the curing agent can be about 18 parts by weight to about 27 parts by weight relative to 100 parts by weight of the preparatory composition, for example, about 19 parts by weight to about 26 parts by weight, for example, about 20 parts by weight to about 26 parts by weight share. When the content of the curing agent satisfies the above range, it is more beneficial to realize the desired performance of the polishing pad.

Where the curing agent comprises an amine compound, the molar ratio of isocyanate (NCO) groups in the preparatory composition to ammonia (NH ₂ ) groups in the curing agent may be about 1:0.60 to about 1 :0.99, for example, about 1:0.60 to about 1:0.90, for example, about 1:0.60 or more and less than about 1:0.90.

The foaming agent is a component for forming a pore structure in the polishing layer, and may contain one selected from the group consisting of a solid foaming agent, a gaseous foaming agent, a liquid foaming agent, and combinations thereof. In an embodiment, the foaming agent may comprise a solid foaming agent, a gaseous foaming agent, or a combination thereof.

The average particle size of the solid foaming agent may be about 5 μm to about 200 μm, eg, about 20 μm to about 50 μm, eg, about 21 μm to about 50 μm, eg, about 21 μm to about 40 μm. The average particle diameter of the solid foaming agent, when the solid foaming agent is the following thermally expanded (expanded) particles, refers to the average particle diameter of the thermally expanded particles themselves, when the solid foaming agent is the following When describing unexpanded particles, it refers to the average particle diameter of particles expanded by heat or pressure.

The solid blowing agent may contain expandable particles. The expandable particles are particles having a property of being expanded by heat or pressure, and their final size in the polishing layer depends on the heat or pressure applied during the preparation of the polishing layer. The expandable particles may comprise thermally expanded (expanded) particles, unexpanded (unexpanded) particles or combinations thereof. The heat-expandable particles, as particles pre-expanded by heat, refer to particles having little or almost no change in size due to heat or pressure applied during the preparation of the polishing layer. The non-expanded particles, as particles without pre-expansion, refer to particles that are expanded by applying heat or pressure during the process of preparing the polishing layer and whose final size is determined.

The expandable particles may include: a resin outer shell; and an expansion-inducing component present inside surrounded by the outer shell.

For example, the sheath may include a thermoplastic resin, and the thermoplastic resin may be one or more selected from the group consisting of vinyl chloride copolymers, acrylonitrile copolymers, methacrylonitrile copolymers, and acrylic copolymers.

The swelling-inducing component may include one selected from the group consisting of hydrocarbons, chlorofluoro compounds, trialkylsilane compounds, and combinations thereof.

Specifically, the hydrocarbon compound may contain ethane (ethane), ethylene (ethylene), propane (propane), propylene (propene), n-butane (n-butane), isobutane (isobutene), n-butane Butene (n-butene), isobutene (isobutene), n-pentane (n-pentane), isopentane (isopentane), neopentane (neopentane), n-hexane (n-hexane), n-heptane (heptane) , petroleum ether (petroleumether) and a combination thereof.

The chlorofluoro compounds may include trichlorofluoromethane (CCl ₃ F), dichlorodifluoromethane (CCl ₂ F ₂ ), Freon-13 (chlorotrifluoromethane, CClF ₃ ), tetrafluorodichloro One of the group consisting of ethane (tetrafluoroethylene, CClF ₂ -CClF ₂ ) and combinations thereof.

The trialkylsilane compound may comprise tetramethylsilane (tetramethylsilane), trimethylethylsilane (trimethylethylsilane), trimethylisopropylsilane (trimethylisopropylsilane), trimethyl-n-propylsilane (trimethyl-n -propylsilane) and combinations thereof.

The solid blowing agent may optionally contain inorganic component treated particles. For example, the solid blowing agent may contain expandable particles treated with an inorganic component. In one embodiment, the solid blowing agent may include expandable particles treated with silicon dioxide (SiO ₂ ) particles. The inorganic component treatment of the solid blowing agent can prevent the aggregation of multiple particles. The chemical, electrical, and/or physical properties of the blowing agent surface of the inorganic component-treated solid blowing agent may differ from solid blowing agents that have not been treated with the inorganic component.

Based on 100 parts by weight of the urethane-based prepolymer, the content of the solid blowing agent may be about 0.5 parts by weight to about 10 parts by weight, for example, about 1 part by weight to about 3 parts by weight, for example , about 1.3 parts by weight to about 2.7 parts by weight, for example, about 1.3 parts by weight to about 2.6 parts by weight.

The type and content of the solid foaming agent can be designed according to the desired pore structure and physical properties of the polishing layer.

The gas blowing agent may contain an inert gas. The gas blowing agent may be added during the reaction of the urethane-based prepolymer with the curing agent to serve as a pore forming element.

The kind of the inert gas is not particularly limited as long as it is a gas that does not participate in the reaction between the urethane-based prepolymer and the curing agent. For example, the inert gas may contain one selected from the group consisting of nitrogen (N ₂ ), argon (Ar), helium (He), and combinations thereof. Specifically, the inert gas may include nitrogen (N ₂ ) or argon (Ar).

The type and content of the gas foaming agent can be designed according to the desired pore structure and physical properties of the polishing layer.

In an embodiment, the foaming agent may comprise a solid foaming agent. For example, the blowing agent may be formed solely of solid blowing agents.

The solid blowing agent may comprise expandable particles, which may comprise thermally expandable particles. For example, the solid blowing agent may consist only of thermally expanded particles. In the case where the non-expanded particles are not included but consist only of thermally expanded particles, the variability of the pore structure is reduced, but the predictability is increased, thus facilitating uniformity in all areas of the polishing layer. stomatal properties.

In one embodiment, the thermally expanded particles may be particles having an average particle diameter of about 5 μm to about 200 μm. The thermally expanded particles may have an average particle size of about 5 μm to about 100 μm, for example, about 10 μm to about 80 μm, for example, about 20 μm to about 70 μm, for example, about 20 μm to about 50 μm, for example, about 30 μm to about 70 μm, for example , about 25 μm to 45 μm, eg, about 40 μm to about 70 μm, eg, about 40 μm to about 60 μm. The average particle diameter is defined as D50 of the thermally expanded particles.

In an embodiment, the thermally expanded particles may have a density of about 30 kg/m³ to about 80 kg/m³, for example, about 35 kg/m³ to about 80 kg/m³, for example, about 35 kg/m³ to about 75 kg/m³, for example , about 38 kg/m³ to about 72 kg/m³, eg, about 40 kg/m³ to about 75 kg/m³, eg, about 40 kg/m³ to about 72 kg/m³.

In one embodiment, the blowing agent may comprise a gaseous blowing agent. For example, the blowing agent may comprise a solid blowing agent and a gaseous blowing agent. Matters related to the solid blowing agent are as described above. The gas blowing agent may comprise nitrogen.

The gaseous blowing agent may be injected using a prescribed injection line during mixing of the urethane-based prepolymer, the solid blowing agent, and the curing agent. The injection rate of the gas blowing agent may be about 0.8L/min to about 2.0L/min, for example, about 0.8L/min to about 1.8L/min, for example, about 0.8L/min to about 1.7L/min , eg, about 1.0 L/min to about 2.0 L/min, eg, about 1.0 L/min to about 1.8 L/min, eg, about 1.0 L/min to about 1.7 L/min.

The composition used to prepare the polishing layer and the window may also contain other additives such as surfactants, reaction rate modifiers, and the like. The titles of "surfactant", "reaction rate regulator" and the like are arbitrarily named based on the main action of the corresponding substance, and the function played by each corresponding substance is not limited to the name of the substance.

The surfactant is not particularly limited, as long as it functions to prevent pores from gathering or overlapping. For example, the surfactant may include silicon-based surfactants.

The surfactant may be used in an amount of about 0.2 parts by weight to about 2 parts by weight based on 100 parts by weight of the urethane-based prepolymer. Specifically, the content of the surfactant relative to 100 parts by weight of the urethane-based prepolymer may be about 0.2 parts by weight to about 1.9 parts by weight, for example, about 0.2 parts by weight to about 1.8 parts by weight, For example, about 0.2 parts by weight to about 1.7 parts by weight, for example, about 0.2 parts by weight to about 1.6 parts by weight, for example, about 0.2 parts by weight to about 1.5 parts by weight, for example, about 0.5 parts by weight to 1.5 parts by weight. In the case where the content of the surfactant is within the range, pores originating from the gas blowing agent can be stably formed and maintained in the mold.

The reaction rate regulator is a regulator that acts to accelerate or delay the reaction, and can be used as a reaction accelerator, a reaction delayer, or both, depending on the purpose of use. The reaction rate regulator may contain a reaction accelerator. For example, the reaction accelerator may be one or more reaction accelerators selected from the group consisting of tertiary amine compounds and organometallic compounds.

Specifically, the reaction rate modifier may comprise a group selected from triethylenediamine, dimethylethanolamine, tetramethylbutylenediamine, 2-methyl-triethylenediamine, dimethylcyclohexylamine, tris Ethylamine, Triisopropanolamine, 1,4-Diazabicyclo(2,2,2)octane, Bis(2-methylaminoethyl)ether, Trimethylaminoethylethanolamine, N, N,N,N,N"-pentamethyldiethylenetriamine, dimethylaminoethylamine, dimethylaminopropylamine, benzyldimethylamine, N-ethylmorpholine, N,N-dimethylamino Ethylmorpholine, N,N-dimethylcyclohexylamine, 2-methyl-2-azanorbornane, dibutyltin dilaurate, stannous octoate, dibutyltin diacetate, dioctyltin diacetate , more than one of the group consisting of dibutyltin maleate, bis(2-ethylhexanoate) dibutyltin and dibutyltin dithiolate. Specifically, the reaction rate regulator can contain benzyldimethylamine , N,N-dimethylcyclohexylamine and triethylamine, and one or more of them.

Based on 100 parts by weight of the urethane-based prepolymer, the reaction rate regulator may be used in an amount of about 0.05 parts by weight to about 2 parts by weight. Specifically, based on 100 parts by weight of the urethane-based prepolymer, the amount of the reaction rate regulator may be about 0.05 parts by weight to about 1.8 parts by weight, for example, about 0.05 parts by weight to about 1.7 parts by weight, For example, about 0.05 parts by weight to about 1.6 parts by weight, for example, about 0.1 parts by weight to about 1.5 parts by weight, for example, about 0.1 parts by weight to about 0.3 parts by weight, for example, about 0.2 parts by weight to about 1.8 parts by weight, for example, About 0.2 parts by weight to about 1.7 parts by weight, for example, about 0.2 parts by weight to about 1.6 parts by weight, for example, about 0.2 parts by weight to about 1.5 parts by weight, for example, about 0.5 parts by weight to about 1 part by weight. When the reaction rate regulator is used within the above-mentioned content range, the curing reaction rate of the prepolymer composition can be properly adjusted, so that a polishing layer with pores of desired size and hardness can be formed.

In the case where the polishing pad includes a buffer layer, the buffer layer plays a role of supporting the polishing layer and absorbing and dispersing external impacts applied to the polishing layer, so that the polishing object can be optimally digested while using the polishing pad. Pads are damaged and defects occur during the polishing process.

The buffer layer may include non-woven fabric or suede, but is not limited thereto.

In one embodiment, the buffer layer may be a non-woven fabric impregnated with resin. The nonwoven fabric may contain one selected from the group consisting of polyester fibers, polyamide fibers, polypropylene fibers, polyethylene fibers, and combinations thereof.

The resin impregnated in the nonwoven fabric may contain polyurethane resin, polybutadiene resin, styrene-butadiene copolymer resin, styrene-butadiene-styrene copolymer resin, acrylonitrile-butadiene One selected from the group consisting of copolymer resins, styrene-ethylene-butadiene-styrene copolymer resins, silicone rubber resins, polyester-based elastomer resins, polyamide-based elastomer resins, and combinations thereof.

In the polishing pad of an embodiment, the hardness (Shore D) of the polishing surface of the polishing layer may be less than about 55, for example, may be more than about 35 and less than about 50, for example, about 40-49. The polishing layer may have a tensile strength of less than about 22 N/mm ² , eg, greater than about 10 N/mm ² and less than about 22 N/mm ² , eg, about 18 N/mm ² to about 20 N/mm ² . The polishing layer may have an elongation of about 200% or more, for example, about 200% to about 300%. The removal rate of the polishing layer can be greater than about 80 μm/hr, eg, about 80 μm/hr to about 100 μm/hr, eg, about 80 μm/hr to about 95 μm/hr. For example, when the hardness of the polishing surface, the tensile strength and elongation of the polishing layer, and the cutting rate of the polishing layer are within the ranges at the same time, it can be evaluated that the processing composition exhibits peak characteristics Corresponding physical and mechanical properties. In this case, the polishing pad including the polishing layer can achieve excellent polishing performance when used in the semiconductor device manufacturing process.

Next, a method for manufacturing the polishing pad will be described.

In another embodiment of the present invention, a method for preparing a polishing pad may be provided, the method comprising: a step of preparing a preliminary composition comprising a prepolymer; preparing a polishing pad comprising the preliminary composition, a foaming agent and a curing agent. a step of preparing a composition for preparing a polishing layer; and a step of preparing a polishing layer by curing the composition for preparing a polishing layer.

The step of preparing the preliminary composition may be a step of preparing a urethane-based prepolymer by reacting a diisocyanate compound with a polyol compound. Matters about the diisocyanate compound and the polyol compound are the same as in the above description about the polishing pad.

The isocyanate group content (NCO%) of the preparatory composition may be from about 5% to about 11% by weight, eg, from about 5% to about 10%, eg from about 5% to about 8.5%. In this case, it may be more advantageous to produce a polishing layer having the chemically bonded structure. The isocyanate group content of the preliminary composition may be derived from terminal isocyanate groups of the urethane-based prepolymer, unreacted unreacted isocyanate groups in the diisocyanate compound, and the like.

The viscosity of the preparatory composition at about 80° C. may be from about 100 cps to about 1000 cps, for example, from about 200 cps to about 800 cps, for example, from about 200 cps to about 600 cps, for example, from about 200 cps to about 550 cps, for example, from about 300 cps to About 500cps.

The blowing agent may comprise a solid blowing agent or a gaseous blowing agent. Matters related to the type of the foaming agent and the like are the same as those described above regarding the polishing pad.

In the case where the foaming agent comprises a solid foaming agent, the step of preparing the polishing layer preparation composition may include: preparing a first preliminary composition by mixing the preliminary composition with the solid foaming agent and a step of preparing a second preliminary composition by mixing the first preliminary composition and a curing agent.

The first preparatory composition may have a viscosity at about 80°C of about 1000 cps to about 2000 cps, eg, about 1000 cps to about 1800 cps, eg, about 1000 cps to about 1600 cps, eg, about 1000 cps to about 1500 cps.

In the case where the foaming agent includes a gas foaming agent, the step of preparing the polishing layer preparation composition may include: a step of preparing a third preliminary composition comprising the preliminary composition and the curing agent; and the step of preparing a fourth preliminary composition by injecting said gas blowing agent in said third preliminary composition.

In one embodiment, the third preparatory composition may further include a solid blowing agent.

In one embodiment, the process of preparing the polishing layer may include: preparing a mold that is preheated to a first temperature; injecting the polishing layer preparation composition into the preheated mold to a step of curing the composition for preparing a polishing layer; and a step of post-curing the composition for preparing a polishing layer which has been cured under a second temperature condition higher than the preheating temperature.

In one embodiment, the temperature difference between the first temperature and the second temperature may be about 10°C to about 40°C, for example, about 10°C to about 35°C, for example, about 15°C to about 35°C.

In one embodiment, the first temperature may be about 60°C to about 100°C, eg, about 65°C to about 95°C, eg, about 70°C to about 90°C.

In one embodiment, the second temperature may be about 100°C to about 130°C, eg, about 100°C to 125°C, eg, about 100°C to about 120°C.

At the first temperature, the step of curing the polishing layer preparation composition may be performed for about 5 minutes to about 60 minutes, for example, for about 5 minutes to about 40 minutes, for example, for about 5 minutes to about 30 minutes, for example , about 5 minutes to about 25 minutes.

The step of post-curing the polishing layer preparation composition cured at the first temperature at the second temperature may be performed for about 5 hours to about 30 hours, for example, for about 5 hours to about 25 hours For example, from about 10 hours to about 30 hours, such as from about 10 hours to about 25 hours, such as from about 12 hours to about 24 hours, such as from about 15 hours to about 24 hours.

The polishing layer finally prepared through the preparation process of the polishing layer may have the following characteristics: After adding 1 g of the polishing layer to a 0.3M potassium hydroxide (KOH) aqueous solution, react in a sealed container at a temperature of 150°C for 48 hours to form The resulting nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition comprises: a first peak, occurring in the range of 15 ppm to 18 ppm, a second peak, occurring in the range of 9 ppm to 11 ppm, and a third peak, occurring in the range of 138 ppm to 143 ppm; And an area ratio of the third peak to the second peak is about 5:1 to 10:1.

For example, an area ratio of the third peak to the second peak may be about 5:1 to about 10:1, eg, about 5:1 to about 8:1.

In one embodiment, the area ratio of the first peak to the second peak of the processing composition may be 10:1 to 10:5, and the area ratio of the first peak to the third peak The ratio can be from 10:5 to 10:10. For example, the area ratio of the first peak to the second peak may be about 10:1 to about 10:5, for example, about 10:1.00 to about 10:1.60, for example, about 10:1.00 or more and about 10 : 1.60 or less, for example, about 10: 1.80 to 10: 2.50, for example, more than about 10: 1.80 and about 10: 2.50 or less. For example, an area ratio of the first peak to the third peak may be 10:5 to 10:10, for example, greater than about 10:5.00 and less than about 10:10.00.

The preparation method of the polishing pad may include the step of processing at least one surface of the polishing layer.

The step of processing at least one surface of the polishing layer may include at least one of the following steps: a first step of forming a groove on the at least one surface of the polishing layer; a second step of line turning; and a third step of roughening at least one surface of the polishing layer.

In the first step, the groove may include at least one of the following grooves: concentric grooves formed at regular intervals from the center of the polishing layer; The center of the layer is continuously connected to radial grooves at the edges of the polishing layer.

In the second step, the line turning process may be performed by cutting the polishing layer to a predetermined thickness using a cutting tool.

In the third step, the roughening treatment may be performed by using a sanding roller to process the surface of the polishing layer.

The preparation method of the polishing pad may further include a step of laminating a buffer layer on the back of the polishing surface of the polishing layer. Matters regarding the buffer layer are the same as those described above regarding the polishing pad.

The polishing layer and the buffer layer may be laminated by using a hot melt adhesive as a medium.

The hot-melt adhesive is coated on the back surface of the polishing surface of the polishing layer, and the hot-melt adhesive is coated on the surface of the buffer layer in contact with the polishing layer, and the polishing layer and the polishing layer are laminated. After the buffer layer makes contact with each surface coated with the hot melt adhesive, the two layers can be welded using a pressure roller.

In yet another embodiment of the present invention, a method for manufacturing a semiconductor device is provided, the method comprising: providing a polishing pad comprising a polishing layer, and setting the polished surface of the polishing object on the polishing surface of the polishing layer so that After the surface to be polished contacts the polishing surface, a step of polishing the polishing object by relatively rotating the two surfaces; the polishing object includes a semiconductor substrate, and the polishing layer has the following characteristics: 1 g of The nuclear magnetic resonance (NMR) ¹³ C spectrum of the processed composition obtained by adding 0.3M potassium hydroxide (KOH) aqueous solution to the polishing layer and reacting at 150°C for 48 hours in a sealed container includes: the first peak at 15ppm to 18ppm; the second peak appears in 9ppm to 11ppm; and the third peak appears in 138ppm to 143ppm; and the area ratio of the third peak to the second peak is about 5:1 to 10 :1.

Matters about the polishing layer and its processing composition are the same as in the above description about the polishing pad. By applying the polishing pad including the polishing layer having the characteristics in the manufacturing method of the semiconductor device, the semiconductor device thus manufactured can exhibit excellent functions derived from the excellent properties of the semiconductor substrate Polished results.

其中， 將所述1g的拋光層加入0.3莫耳濃度的15ml的KOH水溶液中，並在密封容器中以150℃進行48小時的解聚後使用凝膠滲透色譜法（GPC）來測定了所述解聚後的組合物的分子量， 所述Mw是所述解聚組合物的重均分子量， 所述Mn是所述解聚組合物的數均分子量， 所述Mp是所述解聚組合物的峰值分子量。 In yet another embodiment of the present invention, there is provided a method of manufacturing a semiconductor device in which the value of the polishing layer according to Formula 1 can be 0.1 to 0.6: [Formula 1]

Among them, 1 g of the polishing layer was added to 15 ml of KOH aqueous solution with a concentration of 0.3 molar, and depolymerization was carried out at 150° C. for 48 hours in a sealed container, and the gel permeation chromatography (GPC) was used to determine the The molecular weight of the composition after depolymerization, the Mw is the weight average molecular weight of the depolymerization composition, the Mn is the number average molecular weight of the depolymerization composition, and the Mp is the weight average molecular weight of the depolymerization composition peak molecular weight.

Matters about the polishing layer and its processing composition are the same as in the above description about the polishing pad. By applying the polishing pad including the polishing layer having the characteristics in the manufacturing method of the semiconductor device, the semiconductor device thus manufactured can exhibit excellent functions derived from the excellent properties of the semiconductor substrate Polished results.

FIG. 2 is a schematic diagram schematically showing a method of manufacturing a semiconductor device according to an embodiment. Referring to FIG. 2 , in the step of providing a polishing pad including the polishing layer, the polishing pad 110 may be disposed on a flat plate 120 .

The polishing object may include a semiconductor substrate, and the semiconductor substrate 130 may be disposed such that its polished surface is in contact with the polishing surface of the polishing layer of the polishing pad 110 . At this time, the surface to be polished of the semiconductor substrate 130 may be in direct contact with the polishing surface of the polishing layer, or may be in indirect contact through a fluid slurry or the like.

In an embodiment, the manufacturing method of the semiconductor device may further include a step of supplying the polishing slurry 150 on the polishing surface of the polishing layer of the polishing pad 110 . For example, the polishing slurry 150 may be supplied to the polishing surface through the supply nozzle 140 .

The flow rate of the polishing slurry 150 sprayed by the supply nozzle 140 may be about 10 ml/min to about 1000 ml/min, for example, about 10 ml/min to about 800 ml/min, for example, about 50 ml/min to about 500 ml/min , but not limited to this.

The polishing slurry 150 may include silicon dioxide slurry or ceria slurry.

The semiconductor substrate can be brought into contact with the polishing surface by pressing the semiconductor substrate 130 mounted on the polishing head 160 with a predetermined load. The load to press the polished surface of the semiconductor substrate 130 to the polished surface by the polishing head 160, for example, can be selected in the range of about 0.01psi to about 20psi according to the purpose, for example, the The range may be from about 0.1 psi to about 15 psi, but is not limited thereto. When the polishing surface of the polishing layer and the polished surface of the semiconductor substrate are in contact with each other under the action of the load, the polishing layer exhibits the hardness and elongation represented by the peak characteristic, and correspondingly The elasticity and contact area of the semiconductor substrate can be provided to the surface to be polished of the semiconductor substrate, thereby facilitating the polishing rate and defect prevention effect of the semiconductor substrate to reach the target level.

The semiconductor substrate 130 and the polishing pad 100 can rotate relative to each other in a state where their respective surfaces to be polished and the polishing surfaces are in contact with each other. At this time, the rotation direction of the semiconductor substrate 130 and the rotation direction of the polishing pad 100 may be the same or opposite. The rotation speeds of the semiconductor substrate 130 and the polishing pad 110 may be respectively selected within a range of about 10 rpm to about 500 rpm according to purposes, for example, the range may be about 30 rpm to about 200 rpm, but not limited thereto. When the rotational speeds of the semiconductor substrate and the polishing pad satisfy the ranges respectively, the polishing layer exhibits the hardness and elongation represented by the peak characteristic, and the corresponding elasticity and contact area It can be provided to the surface to be polished of the semiconductor substrate, thereby contributing to making the polishing rate and defect prevention effect of the semiconductor substrate reach the target levels.

In one embodiment, in order to keep the polishing surface of the polishing pad 110 in a state suitable for polishing, the manufacturing method of the semiconductor device may further include: polishing the semiconductor substrate 130 by means of a dresser 170 to process the polishing surface of the polishing pad 110.

In one embodiment, in the manufacturing method of the semiconductor device, the semiconductor substrate includes a silicon dioxide (SiO ₂ ) film, the surface to be polished is the surface of the silicon dioxide (SiO ₂ ) film, and the polished The number of surface defects (defects) on the surface to be polished is less than 5, and the average polishing rate of the silicon dioxide (SiO ₂ ) film may be 1500 Å/min to 2500 Å/min, for example, may be Above about 1500 Å/min and less than about 2500 Å/min.

Since, in the manufacturing method of the semiconductor device, the polishing pad including the polishing layer having the above characteristics is used, and the semiconductor substrate having the silicon dioxide (SiO ₂ ) film is used as the polishing object, the polishing rate can be realized and defect prevention performance.

Specific examples of the present invention are given below. However, the examples described below are only for specifically illustrating or explaining the present invention, and are not intended to limit the present invention.

Example 1

2,4-TDI and 2,6-TDI were mixed in the relative weight ratio shown in Table 1 below with respect to 100 weight part of total weights of a diisocyanate component. PTMG and DEG were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing 100 parts by weight of diisocyanate in total and 220 parts by weight of polyol in total with each other. A preliminary composition including a urethane-based prepolymer was prepared by adding the mixed raw materials into a four-necked flask and allowing them to react at 80°C. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 6% by weight. Mix 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent in the preparatory composition, and make the NCO group in the preparatory composition and the NH of the MOCA The molar ratio of ₂ bases is 0.75. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. The preparatory composition was injected into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a discharge rate of 10 kg/min which was preheated to 90°C. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

Example 2

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing 100 parts by weight of diisocyanate in total and 220 parts by weight of polyol in total with each other. A preliminary composition including a urethane-based prepolymer was prepared by adding the mixed raw materials into a four-necked flask and allowing them to react at 80°C. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 8.0% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) is mixed in the preparatory composition as a curing agent, so that the NCO group in the preparatory composition and the NH of the MOCA The molar ratio of ₂ bases is 0.70. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. The preliminary composition was injected into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a discharge rate of 10 kg/min, which was preheated to 100°C. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

Comparative example 1

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing 100 parts by weight of diisocyanate in total and 150 parts by weight of polyol in total with each other. A preliminary composition including a urethane-based prepolymer was prepared by adding the mixed raw materials into a four-necked flask and allowing them to react at 80°C. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) is mixed in the preparatory composition as a curing agent, so that the NCO group in the preparatory composition and the NH of the MOCA The molar ratio of ₂ bases is 0.96. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. Inject the preparatory composition into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a speed of 10 kg/min, which is preheated to 90 ° C, and nitrogen (N ₂ ) is used as a gas blowing agent at a rate of 1.0 The injection speed of L/min is injected into the mold, and the injection time is the same as that of the preparation composition. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

Comparative example 2

2,4-TDI, 2,6-TDI, and H ₁₂ MDI were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the diisocyanate component. PTMG and DEG were mixed in relative weight ratios shown in Table 1 below with respect to 100 parts by weight of the total weight of the polyol component. A mixed raw material was prepared by mixing 100 parts by weight of diisocyanate in total and 150 parts by weight of polyol in total with each other. A preliminary composition including a urethane-based prepolymer was prepared by adding the mixed raw materials into a four-necked flask and allowing them to react at 80°C. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9.2% by weight. 4,4'-methylenebis(2-chloroaniline) (MOCA) is mixed in the preparatory composition as a curing agent, so that the NCO group in the preparatory composition and the NH2 of the MOCA The base molar ratio becomes 0.94. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. The preparatory composition was injected into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a discharge speed of 10 kg/min, which was preheated to 95°C. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

After processing the polishing layers of Examples 1 to 2 and Comparative Examples 1 to 2 to a thickness of 2 mm, concentric circles were formed on the polishing surface by performing a groove processing step on the polishing surface. groove. Next, a buffer layer having a structure in which a polyester resin nonwoven fabric is impregnated with a urethane resin and a thickness of 1.1 mm is prepared, and then a hot-melt coating is applied on the back surface of the polishing surface and the attachment surface of the buffer layer. After the adhesive is applied, it is laminated using a pressure roller. Thus, a final polishing pad was prepared.

Experimental Example 1: Experimental Example 1: Nuclear Magnetic Resonance (NMR) ¹³ C Spectrum of the Preliminary Composition

For each of the preliminary compositions of Examples 1 to 2 and Comparative Examples 1 to 2, 5 mg of the preliminary composition was dissolved in deuterated chloroform (CDCl ₃ ) and a nuclear magnetic resonance (NMR) device was used at room temperature ¹³ C-NMR analysis was carried out (JEOL 500 MHz, 90° pulse). Pulse NMR measurement was carried out under the following conditions: pulse width 90°pulse; 2.0μs; repetition time 2s; scan count 5100; measurement temperature was room temperature (RT) (25°C).

Experimental Example 2: Nuclear Magnetic Resonance (NMR) ¹³ C Spectrum of Processed Composition

For each of the polishing layers of Examples 1 to 2 and Comparative Examples 1 to 2, 1 g of the polishing layer was added to 15 ml of 0.3 M potassium hydroxide (KOH) aqueous solution, and in a sealed container with a volume of 48 ml In , the processing composition was prepared by reacting at a temperature of 150° C. for 48 hours. After dissolving 5 mg of the processing composition in CDCl ₃ , ¹³ C-NMR analysis was performed at room temperature using a nuclear magnetic resonance (NMR) apparatus (JEOL 500 MHz, 90° pulse).

Experimental Example 3: Evaluation of Physical Properties of Polishing Layer or Polishing Pad

(1) Hardness

After processing each polishing layer of the Examples 1 to 2 and the Comparative Examples 1 to 2 to a thickness of 2 mm, samples were prepared by cutting the length and width into sizes of 5 cmХ5 cm, respectively. Shore D hardness was measured using a durometer after storing the sample at a temperature of 25° C. for 12 hours.

(2) Tensile strength

After processing each of the polishing layers of the Examples 1 to 2 and the Comparative Examples 1 to 2 to a thickness of 2 mm, samples were prepared by cutting the length and width into sizes of 4 cmХ1 cm, respectively. The highest strength value of the sample before fracture was measured at a speed of 50mm/min using the Universal Testing Machine (UTM).

(3) Elongation

After processing each of the polishing layers of the Examples 1 to 2 and the Comparative Examples 1 to 2 to a thickness of 2 mm, samples were prepared by cutting the length and width into sizes of 4 cmХ1 cm, respectively. A universal testing machine (UTM) was used to measure the maximum deformation length of the sample before fracture at a speed of 50 mm/min, and then the ratio of the initial length to the maximum deformation length was shown in percentage (%).

(4) cutting rate

For each polishing pad prepared using the polishing layers of Examples 1 to 2 and Comparative Examples 1 to 2 according to the above method, deionized water (deionized water) was used to precondition the polishing pad for 10 min. -conditioning), the polishing pad was conditioned by spraying deionized water for 1 hour. The thickness change during the dressing process was measured, and the change in thickness (μm/hr) was calculated as the cutting rate of the polishing pad. The equipment used for dressing is AP-300HM of CTS Company, the dressing pressure is 6lbf, the rotation speed is 100~110rpm, and the disk used for dressing is CI-45 of Saesol Company.

Experimental Example 4: Polishing Performance Evaluation

After preparing polishing pads employing the polishing layer 1 of Examples 1 to 2 and Comparative Examples 1 to 2, the polishing performance was evaluated as follows.

Silicon oxide (SiO2) is deposited on silicon wafers with a diameter of 300mm by a chemical vapor deposition (CVD) process. Install the polishing pad on the CMP machine, and set the silicon wafer so that the silicon oxide layer of the silicon wafer faces the polishing surface of the polishing pad. The sintered ceria slurry was supplied onto the polishing pad at a rate of 250 ml/min, while the silicon wafer was pressed onto the polishing surface with a load of 4.0 psi, and the polishing pad was The silicon dioxide film was polished for 60 seconds by setting the rotation speed of the silicon wafer at 150 rpm. After polishing, the silicon wafer was removed from the carrier, installed on a spin dryer (spin dryer), washed with distilled water, and dried with nitrogen for 15 s.

(1) Average polishing rate

Film thickness changes of dried silicon wafers before and after polishing were measured using a spectroscopic interference wafer thickness meter (SI-F80R, Kyence Corporation). The polishing rate was then determined using the following formula. In this way, the average polishing rate was measured five times in total, and the average value was determined as the average polishing rate. Polishing rate (Å/min) = polished thickness of silicon wafer (Å) / polishing time (min)

(2) defects

Polishing was performed in the same manner as the method for measuring the polishing rate, and the number of defects such as scratches (scratch) was calculated by visually observing the polished surface of the polishing target. Specifically, after polishing, move the silicon wafer to the cleaner (Cleaner), use 1% hydrogen fluoride (HF) and purified water (DIW), 1% nitric acid (H ₂ NO ₃ ) and purified water (DIW) to carry out Wash for 10s. Then, the silicon wafer was moved to a spin dryer, washed with purified water (DIW), and dried with nitrogen (N ₂ ) for 15 s. Then, using defect inspection equipment (Tenkor, XP+), the changes of defects before and after polishing of the dried silicon wafer were observed with naked eyes.

The results of the experimental examples 1 to 4 are shown in Table 1 below.

[Table 1] project Example 1 Example 2 Comparative example 1 Comparative example 2 Preparation Composition Diisocyanate 2,4-TDI 96 80 73 71 2,6-TDI 4 5 17 16 H ₁₂ MDI - 15 10 13 Total 100 100 100 100 Polyol PTMG (Mw1000) 90.0 97.5 90.8 89.9 DEG (Mw106) 10.0 2.5 9.2 10.1 Total 100 100 100 100 NCO group content (% by weight) of the preparation composition 6 8.0 9 9.2 Amine curing agent The molar ratio of NCO to curing agent _NH2 in the preparation composition 0.75 0.70 0.96 0.94 Process conditions Prepolymer preparation reaction temperature (°C) 80 80 80 80 Curing mold preheating temperature (°C) 90 100 90 95 Post-curing temperature (°C) 110 110 110 110 Preparatory Composition ¹³ CNMR Peak position (ppm) The fourth peak (17.5~20) 17.627 17.713 17.694 17.682 The fifth peak (16~17.5) 17.226 17.293 17.026 16.997 area ratio Fourth Peak: Fifth Peak 3.89:1 6.02:1 3.18:1 1.67:1 Processing Composition ¹³ CNMR Peak position (ppm) The first peak (15~18) 16.263 17.093 16.549 16.196 Second peak (9~11) 10.006 10.000 10.292 9.930 The third peak (138~143) 140.824 143.104 141.082 160.853 area ratio 3rd peak: 2nd peak 5.31:1 5.25:1 3.15:1 3.34:1 1st peak: 2nd peak 10:1.08 10:1.60 10:1.72 10:1.66 1st peak: 3rd peak 10:5.74 10:8.40 10:5.40 10:5.52 Physical Properties of Polishing Layer or Pad Hardness (Shore D) 43 45 58.4 56.2 Tensile strength (N/mm ² ) 14.5 18.5 21.4 22.2 Elongation (%) 230.8 240.2 94.4 107.5 Polishing pad removal rate (μm/hr) 84.5 90.2 51.2 51.3 Polishing performance Average polishing rate (Å/min) 2357 2345 3724 3324 Number of defects (ea) 4 5 0.5 1

Referring to the Table 1, in the polishing layer of the Examples 1 to 2, the nuclear magnetic resonance (NMR) ¹³ C spectrum of the processing composition processed under the specified conditions includes: the first peak appears at 15ppm to 18ppm, The second peak appears in 9ppm to 11ppm, and the third peak appears in 138ppm to 143ppm; and as applicable, the area ratio of the third peak to the second peak is 5:1 to 10:1 The pad of the polishing layer can be seen from the corresponding characteristics such as hardness, tensile strength, elongation and cutting rate, and the polishing result of the semiconductor substrate is very excellent.

In contrast, in the case of the polishing layers of Comparative Examples 1 and 2, the area ratio of the third peak to the second peak was out of the range of 5:1 to 10:1, so it was confirmed that the Compared with the polishing layer of Examples 1 to 2, the physical properties are higher in hardness and tensile strength, and lower in elongation and cut rate. Thus, it can be confirmed that the polishing pads of Comparative Examples 1 and 2 cannot provide the target level of polishing performance to the surface to be polished as the polishing pads of Examples 1 and 2, and thus are inferior in average polishing rate and defects.

Comparative example 3

The diisocyanate component and the polyol component were mixed in the composition ratio shown in Table 2 below, put into a four-necked flask, and reacted at 80° C. to prepare a preliminary composition containing a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9.2% by weight. Mix 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent in the preparatory composition, and make the NCO group in the preparatory composition and the NH of the MOCA The molar ratio of ₂ bases is 0.94. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. The preparatory composition was injected into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a discharge speed of 10 kg/min, which was preheated to 95°C. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

Comparative example 4

The diisocyanate component and the polyol component were mixed in the composition ratio shown in Table 2 below, put into a four-necked flask, and reacted at 80° C. to prepare a preliminary composition containing a urethane-based prepolymer. The content of isocyanate groups (NCO groups) in the preliminary composition was adjusted to 9.5% by weight. Mix 4,4'-methylenebis(2-chloroaniline) (MOCA) as a curing agent in the preparatory composition, and make the NCO group in the preparatory composition and the NH of the MOCA The molar ratio of ₂ bases is 0.92. In addition, 1.0 parts by weight of expandable particles and a solid foaming agent (AkzoNobel) were mixed into the preliminary composition. The preliminary composition was injected into a mold with a width of 1000 mm, a length of 1000 mm and a height of 3 mm at a discharge rate of 10 kg/min, which was preheated to 100°C. Next, a polishing layer was prepared by post-curing the preparatory composition at a temperature of 110°C.

[Table 2] project Example 1 Example 2 Comparative example 1 Comparative example 3 Comparative example 4 Preparation Composition Diisocyanate 2,4-TDI 96 80 73 72 70 2,6-TDI 4 5 17 16 15 H ₁₂ MDI - 15 10 12 15 Total 100 100 100 100 100 Polyol PTMG (Mw1000) 90.0 97.5 90.8 89.9 89.9 DEG (Mw106) 10.0 2.5 9.2 10.1 10.1 Total 100 100 100 100 100 Preparatory composition NCO group content (weight %) 6 8 9 9.2 9.5 Amine curing agent The molar ratio of NCO in the preparation composition to _NH of the curing agent 0.75 0.70 0.96 0.94 0.92 Process conditions Prepolymer preparation reaction temperature (°C) 80 80 80 80 80 Curing mold preheating temperature (°C) 90 100 90 95 100 Post-curing temperature (°C) 110 110 110 110 110

Experimental example 5: GPC measurement of processed composition

Add about 1 g of the polishing layers of the examples and comparative examples into 15 ml of about 0.3 M KOH aqueous solution. Then, the KOH solution mixed with the polishing layer was placed in a sealed pressure vessel having a volume of about 48 ml, and depolymerization was performed at a temperature of 150° C. under a pressure of about 3 atmospheres for about 48 hours. Then, the depolymerized composition was extracted with dioxymethane.

Mw (weight average molecular weight), Mn (number average molecular weight) and Mp (peak molecular weight) of the extracted composition were measured by gel permeation chromatography (GPC) instrument. And as a control, the Mw, Mn, and Mp values of the urethane-based prepolymer contained in the preliminary composition of Example 1 were measured.

其中， Mw為解聚後的組合物的重均分子量， Mn為解聚後的組合物的數均分子量， Mp為解聚後的組合物的峰值分子量。 The GPC instrument and measurement conditions are as follows: Measuring instrument: Agilent 1260 Infinity GPC Injection rate (Flow rate): 1ml/min in THF Injection volume: 100ul Column temperature (Column Temp): 40°C Detector: RI column (Column ): TSKgel G1000HxL Molecular weight size 5060 The value of the following formula 1 was calculated using the GPC measurement value: [Formula 1]

Wherein, Mw is the weight average molecular weight of the composition after depolymerization, Mn is the number average molecular weight of the composition after depolymerization, and Mp is the peak molecular weight of the composition after depolymerization.

[table 3] MP mn mw PDI Equation 1 value Example 1 2418 2320 2559 1.1 0.41 Example 2 2359 2163 2560 1.18 0.49 Comparative example 1 3229 2725 3331 1.22 0.83 Comparative example 3 3158 2732 3347 1.23 0.69 Comparative example 4 3216 2730 3247 1.19 0.94 Urethane based prepolymer 4032 3040 4281 1.41 0.80

Based on the measurement results, comparing the GPC measurement results of the urethane-based prepolymer with the GPC measurement results of Examples and Comparative Examples, it can be confirmed that the position of degradation by depolymerization is different from that of the prepolymer.

Specifically, the urethane-based prepolymer is prepared into a polishing layer by curing, and then the portion degraded by depolymerization is different from the portion combined with the prepolymer when polymerized. Table 3 confirms that the Mp, Mn, and Mw of Examples 1 and 2 of the present invention are different from those of the comparative example, and that there is also a difference in the PDI value. In addition, it was confirmed that the values according to Formula 1 of Examples 1 and 2 also satisfied the scope of the present invention, and the comparative examples and prepolymers were outside the scope of the present invention.

Experimental Example 6: Physical Property Evaluation of Polishing Layer or Polishing Pad and Polishing Performance Evaluation

(1) Average pore size

The diameter of the pores of the polishing layer was measured, and the diameter of the pores was measured using a particle size analyzer, and the average pores refer to D50.

(2) specific gravity

The specific gravity of the window prepared according to the examples and comparative examples was measured, and the polishing pad was cut into a size of 2cmХ2cm (thickness: 2mm) and left to stand for 16 hours at a temperature of 25°C and a humidity of 50±5%. Then, the density was obtained by measuring the initial weight and the weight when soaked in water using an electronic density meter (Electronic densimeter).

(3) Chatter mark detection

After using the polishing pad to carry out the polishing processes recorded in the examples and comparative examples, the defect detection equipment (AITXP+, KLATencor company) was used to measure the residue on the surface of the wafer (monitor wafer) after polishing under the conditions of threshold150 and die filter threshold280 Residues, scratches, and chatter marks.

The evaluation results of the Examples and Comparative Examples according to Experimental Examples 3, 4 and 6 are shown in Table 4 below.

[Table 4] Example 1 Example 2 Comparative example 1 Comparative example 3 Comparative example 4 Hardness (Shore D) 43.5 53.2 56.2 57.7 58 Average Pore size (um) twenty one 11.2 24.1 20.7 21.5 Specific gravity (g/cc) 0.8 0.8 0.8 0.8 0.8 Tensile strength (N/mm ² ) 19.5 19.82 23.2 22.3 22.3 Elongation (%) 240.5 81.3 98.2 107.5 109.1 Average polishing rate (Å/min) 1825 3458 3724 3357 3650 pit (pit)/residue 2 2.5 3 4 3.5 chatter mark 0 0.5 1 0 0.5

According to the experimental results, it was confirmed that the average polishing rate of the polishing pad of Example 1 was lower than that of other polishing pads, but exhibited a very excellent effect on silicon wafer defects.

In addition, in the case of Example 2, it was confirmed that the average polishing rate was maintained at the same level as compared with the comparative example, and an excellent effect was exhibited on wafer defects. This is because the polishing layer has a small average pore size and excellent tensile strength and elongation properties.

100, 110, 200: polishing pad 10: Polishing layer 11: First surface 12: Second surface 13: Groove 20: buffer layer 30: The first adhesive layer 40: Second adhesive layer 50: Preparatory Composition 60: Curing Structures 70: Processing Composition 120: tablet 130: Semiconductor substrate 140: supply nozzle 150: polishing slurry 160: Polishing head 170: Dresser

1A and 1B are diagrams schematically showing a cross-section of the polishing pad according to an embodiment.

FIG. 2 is a process diagram of a method of manufacturing a semiconductor device according to an embodiment.

FIG. 3 is a schematic diagram illustrating exemplary preparatory compositions, cured structures, and processed compositions.

10: Polishing layer

11: First surface

12: Second surface

13: Groove

20: buffer layer

100: polishing pad

Claims (10)

A polishing pad comprising a polishing layer comprising a cured product of a preliminary composition containing a urethane-based prepolymer, the preliminary composition comprising reactants of an isocyanate compound and a polyol compound, relative to the The total amount of isocyanate compounds is 100 parts by weight, the total amount of polyol compounds is 150 to 240 parts by weight, 1g of the polishing layer is added to a 0.3M potassium hydroxide aqueous solution, and in a sealed container at 150 The nuclear magnetic resonance ¹³ C spectrum of the processed composition reacted at ℃ for 48 hours includes: a first peak, appearing in 15ppm to 18ppm; a second peak, appearing in 9ppm to 11ppm; and a third peak, appearing in 138ppm to 143ppm appears, the area ratio of the third peak to the second peak is 5:1 to 10:1. The polishing pad according to claim 1, wherein the area ratio of the first peak to the second peak is 10:1 to 10:5, and the area ratio of the first peak to the third peak is 10:5 to 10:10. The polishing pad according to claim 1, wherein the nuclear magnetic resonance ¹³ C spectrum of the preparation composition shows the fourth peak and the fifth peak in order of peak position values from large to small in the range of 16ppm to 20ppm, said The area ratio of the fourth peak to the fifth peak is 1:1 to 10:1, the isocyanate compound includes an aromatic diisocyanate compound, and the polyol compound includes: a weight average molecular weight of about 100 g/mol or more and less than A low-molecular-weight polyol of about 300 g/mol; and a high-molecular-weight polyol with a weight average molecular weight of not less than about 300 g/mol and not more than about 1800 g/mol, the isocyanate compound comprising 2,4-toluene diisocyanate, and the preliminary combination The product comprises a urethane-based prepolymer comprising a first unit structure of 2,4-toluene diisocyanate derived from a urethane reaction at one end and a urethane-derived urethane reaction at both ends. At least one of the second unit structures of 2,4-toluene diisocyanate, the isocyanate group content of the preliminary composition is 5% by weight to 11% by weight. The polishing pad according to claim 1, wherein the value of the polishing layer according to the following formula 1 is 0.1 to 0.6,

Wherein, the molecular weight of the processing composition is determined by gel permeation chromatography, the Mw is the weight average molecular weight of the depolymerization composition, the Mn is the number average molecular weight of the depolymerization composition, and the Mp is the depolymerization composition peak molecular weight. The polishing pad according to claim 1, wherein the number average molecular weight of the processing composition is 18000g/mol to 2800g/mol, the weight average molecular weight is 2000g/mol to 3000g/mol, and the peak molecular weight is 2000g/mol to 3000g /mol, the dispersion is 1 to 1.2. A preparation method of a polishing pad, comprising the following steps: a first step of preparing a preparatory composition comprising reactants of an isocyanate compound and a polyol compound; a second step of preparing a preparatory composition comprising the preparatory composition, a foaming agent and a curing agent a composition for preparing a polishing layer; and a third step of preparing a polishing layer by curing the composition for preparing a polishing layer, with respect to 100 parts by weight of the total amount of the isocyanate compound, the total amount of the polyol compound is 150 Parts by weight to 240 parts by weight, in the polishing layer, add 1 g of the polishing layer to a 0.3M potassium hydroxide aqueous solution, and react in a sealed container at a temperature of 150° C. for 48 hours. The nuclear magnetic resonance of the processing composition ¹³ C spectrum includes: a first peak, appearing in 15ppm to 18ppm; a second peak, appearing in 9ppm to 11ppm; and a third peak, appearing in 138ppm to 143ppm, the third peak and the second peak The area ratio is 5:1 to 10:1. The method for preparing a polishing pad according to claim 6, wherein the area ratio of the first peak to the second peak is 10:1 to 10:5, and the area ratio of the first peak to the third peak The area ratio is 10:5 to 10:10, the nuclear magnetic resonance ¹³ C spectrum of the preparation composition shows the fourth peak and the fifth peak in the order of peak position values from large to small in 16ppm to 20ppm, the first The area ratio of the four peaks to the fifth peak is 1:1 to 10:1. The method for preparing a polishing pad according to claim 6, wherein the value of the polishing layer according to the following formula 1 is 0.1 to 0.6,

Wherein, the molecular weight of the processing composition is determined by gel permeation chromatography, the Mw is the weight average molecular weight of the depolymerization composition, the Mn is the number average molecular weight of the depolymerization composition, and the Mp is the depolymerization composition peak molecular weight. A method of manufacturing a semiconductor device, comprising the steps of: providing a polishing pad comprising a polishing layer; and setting a polished surface of a polishing object on a polishing surface of the polishing layer so that the polished surface contacts the polishing surface , and then a step of polishing the polishing object by relatively rotating the polishing surface and the polished surface, the polishing object includes a semiconductor substrate; the polishing layer includes a preparation containing a urethane-based prepolymer The cured product of the composition, the preliminary composition includes reactants of isocyanate compound and polyol compound, relative to 100 parts by weight of the total amount of isocyanate compound, the total amount of the polyol compound is 150 parts by weight to 240 parts by weight , in the polishing layer, 1 g of the polishing layer was added to 0.3M potassium hydroxide aqueous solution, and the nuclear magnetic resonance ¹³ C spectrum of the processing composition reacted at 150° C. for 48 hours in a sealed container included: the first peak , appearing in 15ppm to 18ppm; the second peak, appearing in 9ppm to 11ppm; and the third peak, appearing in 138ppm to 143ppm, the area ratio of the third peak to the second peak is 5:1 to 10:1. The method of manufacturing a semiconductor device according to claim 9, wherein the value of the polishing layer according to the following formula 1 is 0.1 to 0.6,

Wherein, the molecular weight of the processing composition is determined by gel permeation chromatography, the Mw is the weight average molecular weight of the depolymerization composition, the Mn is the number average molecular weight of the depolymerization composition, and the Mp is the depolymerization composition peak molecular weight.

Images